docs: def main(self, args=None):
          """Enter filesystem service loop."""
  
          if get_compat_0_1():
              args = self.main_0_1_preamble()
  
          d = {'multithreaded': self.multithreaded and 1 or 0}
          d['fuse_args'] = args or self.fuse_args.assemble()
  
          for t in 'file_class', 'dir_class':
              if hasattr(self, t):
                  getattr(self.methproxy, 'set_' + t)(getattr(self,t))
  
          for a in self._attrs:
              b = a
              if get_compat_0_1() and a in self.compatmap:
                  b = self.compatmap[a]
              if hasattr(self, b):
                  c = ''
                  if get_compat_0_1() and hasattr(self, a + '_compat_0_1'):
                      c = '_compat_0_1'
                  d[a] = ErrnoWrapper(self.lowwrap(a + c))
  
          try:
              main(**d)
          except FuseError:
              if args or self.fuse_args.mount_expected():
                  raise